An operating method of a memory device includes storing position information regarding a codeword including an erasure and erasure information including position information regarding the erasure in a memory region, loading the position information regarding the codeword to a row decoder and a column decoder, determining whether a read address corresponding to a read instruction is identical to the position information regarding the codeword including the erasure, in response to the read instruction from a host, transmitting the position information of the erasure to an error correction code (ECC) decoder, when the read address is identical to the position information regarding the codeword including the erasure, and correcting, by the ECC decoder, an error in a codeword received from a memory cell array using the position information regarding the erasure.